Recently, with an increasing number of Internet users, electronic mail has been widespread not only by personal computers (PCs) but also by mobile telephones. Correspondingly, there are increasing numbers of pieces of electronic mail for advertisement, solicitation, etc. that is, unsolicited commercial mail.
There are ever-growing numbers of pieces of unsolicited commercial mail, and communication common carriers and mail receivers have proposed and performed various countermeasures against the unsolicited commercial mail.
Patent Document 1 discloses a method against general unsolicited commercial mail.
The patent document 1 is to prevent mail including specific mail addresses and character strings from being distributed to users by registering the specific addresses and character strings in a mail server and filtering out the mail including the specific addresses and character strings.
In the conventional mail services of the patent document 1 etc., mail from a desired mail address can be received by registering an address with a receive permit according to the operation on the Web screen after a connection to a mail server.
Patent Document 1: Japanese Laid-open Patent Publication No. 2005-44323